This invention relates to dyes, to inks, to compositions and to their use in ink jet printing (xe2x80x9cIJPxe2x80x9d). IJP is a non-impact printing technique in which droplets of ink are ejected through a fine nozzle onto a substrate without bringing the nozzle into contact with the substrate.
There are many demanding performance requirements for dyes and inks used in IJP. For example they desirably provide sharp, non-feathered images having good waterfastness, light-fastness and optical density. The inks are often required to dry quickly when applied to a substrate to prevent smudging, but they should not form a crust over the tip of an ink jet nozzle because this will stop the printer from working. The inks should also be stable to storage over time without decomposing or forming a precipitate which could block the fine nozzle.
According to the present invention there is provided a compound of Formula (1) and salts thereof: 
wherein:
B1 and B2 are each independently xe2x80x94SO3H, xe2x80x94COOH, xe2x80x94CF3, optionally substituted alkoxy, optionally substituted alkyl or xe2x80x94PO3H2;
Q is an organic linking group;
R1 and R2 are each independently H or optionally substituted alkyl;
each A independently is N, Cxe2x80x94Cl, Cxe2x80x94CN or Cxe2x80x94NO2;
Z1 and Z2 are each independently xe2x80x94SR3, xe2x80x94OR4, xe2x80x94NR5R6 or halogen;
R3, R4, R5 and R6 are each independently H, optionally substituted alkyl, optionally substituted aryl or optionally substituted aralkyl; or
R5 and R6 together with the nitrogen to which they are attached form an optionally substituted five or six membered ring;
provided that Q is not of the formula: 
B1 and B2 are preferably attached ortho to the azo group. It is also preferred that B1 and B2 are each independently xe2x80x94SO3H, xe2x80x94COOH, xe2x80x94CF3, optionally substituted C1-4-alkoxy, optionally substituted C1-4-alkyl or xe2x80x94PO3H2, more preferably xe2x80x94SO3H, xe2x80x94COOH or xe2x80x94CF3 and especially xe2x80x94SO3H. When B1 or B2 is substituted, the substituent(s) is/are preferably selected from xe2x80x94OH, xe2x80x94SO3H, xe2x80x94COOH, xe2x80x94NH2, C1-4-hydroxyalkyl, C1-4-hydroxyalkoxy and C1-4-alkoxy.
Preferably each A is N.
Preferably R1 and R2 are each independently H or optionally substituted C1-4-alkyl, more preferably H or C1-4-alkyl optionally substituted by hydroxy, carboxy, sulpho or cyano. It is especially preferred that R1 and R2 are methyl or H, more especially H.
The organic linking group Q is preferably an optionally substituted piperazinylene group, or a group of the formula xe2x80x94X1xe2x80x94Lxe2x80x94X2xe2x80x94 wherein X1 and X2 are each independently an optionally substituted piperazinylene group, xe2x80x94Sxe2x80x94, xe2x80x94Oxe2x80x94 or xe2x80x94NR7xe2x80x94 wherein R7 is H, optionally substituted alkyl or optionally substituted aryl, and L is a divalent organic linking group.
Preferably R7 is H, C1-4-alkyl or xe2x80x94C1-4-hydroxyalkyl, more preferably H or methyl, especially H.
Preferred divalent organic linking groups represented by L are alkylene, preferably C1-20-alkylene, more preferably C2-10-alkylene, each of which is optionally interrupted; alkenylene, preferably C2-6-alkenylene; arylene, preferably arylene containing up to ten carbon atoms, more preferably phenylene or naphthylene, especially 1,3- or 1,2-phenylene; aralkylene, more preferably C7-10-aralkylene, especially phenylene-C1-6-alkylene more especially -phenylene-CH2xe2x80x94; and two arylene groups joined together either directly or through a vinyl, oxygen, nitrogen or sulphur link; each of the above divalent organic linking groups may be substituted or unsubstituted.
The optional substituent(s) on L are preferably selected from alkyl optionally substituted by hydroxy, carboxy or sulpho, preferably hydroxy-C1-4-alkyl, carboxy-C1-4-alkyl or sulpho-C1-4-alkyl; alkoxy, preferably C1-4-alkoxy and especially methoxy; phenyl optionally substituted by C1-4alkyl, carboxy, hydroxy, sulpho, amino or nitro; halo, preferably F or Cl; xe2x80x94SO3H; xe2x80x94COOH; xe2x80x94OH; xe2x80x94CN; or xe2x80x94NO2.
When L is an alkylene group it is preferably C210-alkylene optionally interrupted by xe2x80x94Oxe2x80x94; xe2x80x94Sxe2x80x94; optionally substituted arylene, especially optionally substituted phenylene; xe2x80x94NR8xe2x80x94; xe2x80x94C(O)xe2x80x94; xe2x80x94CO(O)xe2x80x94; or an optionally substituted piperazinylene group, wherein R8 is H, C1-4-alkyl, or xe2x80x94C1-4-hydroxyalkyl, more preferably H. When the interrupting group is a substituted piperazinylene group it is preferably substituted by C1-6-alkyl optionally substituted by hydroxy, carboxy or sulpho.
An especially preferred interrupted alkylene group is of the formula: 
wherein:
R9 and R10 each independently is H or C1-4-alkyl optionally substituted by hydroxy, sulpho or carboxy.
Preferably R9 and R10 are H.
Examples of optionally substituted alkylene and alkenylene groups represented by L include: ethylene; 1,2- and 1,3-propylene; 2-hydroxy-1,3-propylene; 1-, and 2-phenyl-1,3-propylene; 1,4-, 2,3- and 2,4-butylene; 2-methyl-1,3-propylene; 2-(4xe2x80x2-sulphophenyl)-1,3-propylene; 2-methyl-2,4-pentylene; 2,2-dimethyl-1,3-propylene; 1-chloro-2,3-propylene; 1,6- and 1,5-hexylene; 1-carboxy-ethylene 1-carboxy-1,5-pentylene; 2,7-heptylene; 3-methyl-1,6-hexylene; xe2x80x94CH2CHxe2x95x90CHCH2xe2x80x94 and 1-(methoxycarbonyl)-1,5-pentylene.
Examples of optionally interrupted alkylene groups represented by L include xe2x80x94CH2NHCH2xe2x80x94; xe2x80x94CH2CH2OCH2CH2xe2x80x94; xe2x80x94(CH2)3O(CH2)2O(CH2)OCH2OCH2xe2x80x94; xe2x80x94CH2CH2SCH2CH2xe2x80x94; o-, m- and p-xylylene and 
A preferred aralkyl group represented by L is of the Formula (2): 
wherein:
each R11 independently is H, C1-4-alkoxy, F, Cl, xe2x80x94SO3H, xe2x80x94COOH, xe2x80x94OH, xe2x80x94CN, xe2x80x94NO2 or C1-4-alkyl optionally substituted by xe2x80x94OH, xe2x80x94COOH or xe2x80x94SO3H; and
y is 1 to 4.
Preferably y is 1, 2 or 3, more preferably 1.
We have found that compounds wherein L is of the Formula (2) exhibit a high solubility in aqueous media and when incorporated into an ink, the ink exhibits very good operability in ink jet printers.
Examples of preferred arylene and aralkylene groups include xe2x80x94C6H4xe2x80x94CH2xe2x80x94, xe2x80x94C6H4xe2x80x94CH2CH2xe2x80x94, 1,2-, 1,3- and 1,4-phenylene and 1,4-naphthylene.
When L is two arylene groups joined together directly it is preferably an optionally substituted biphenylene group, more preferably optionally substituted 4,4xe2x80x2-biphenylene.
When L is a two arylene groups joined by a divalent linking group it is preferably two of the hereinbefore defined arylene groups (especially optionally substituted phenylene) joined together by a linking group selected from xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR8xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 and C2-6-alkylene optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94NR8xe2x80x94, wherein R8 is as hereinbefore defined. Examples of two arylene groups joined by a divalent linking group include diphen-4,4xe2x80x2-ylene-methane, xe2x80x94C6H4xe2x80x94CH2CH2xe2x80x94C6H4xe2x80x94, xe2x80x94C6H4xe2x80x94CHxe2x95x90CHxe2x80x94C6H4xe2x80x94, xe2x80x94C6H4xe2x80x94Oxe2x80x94C6H4xe2x80x94, xe2x80x94C6H4xe2x80x94Sxe2x80x94C6H4xe2x80x94 and xe2x80x94C6H4xe2x80x94NHCH2xe2x80x94C6H4xe2x80x94.
When Q, X1 or X2 is an optionally substituted piperazinylene group it is preferably of the Formula (3): 
wherein R9 and R10 are each independently as hereinbefore defined.
Where one or both of X1 and X2 is an optionally substituted piperazinylene group, Q (i. e. the group X1LX2xe2x80x94) is preferably one of the following formulae: 
wherein R7 is as hereinbefore defined.
In a preferred embodiment Q is an optionally substituted piperazinylene group or Q is a group of the formula xe2x80x94X1xe2x80x94Lxe2x80x94X2xe2x80x94 wherein X1 and X2 are each independently selected from optionally substituted piperazinylene, xe2x80x94Sxe2x80x94 or xe2x80x94NR7xe2x80x94 wherein R7 is as hereinbefore defined; and L is a group of Formula (2), 1,3-phenylene, or C2-6-alkylene optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, phenylene, xe2x80x94NR8xe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94CO(O)xe2x80x94 or an optionally substituted piperazinylene group, wherein R8 is as hereinbefore defined. In this embodiment preferred optionally substituted piperazinylene groups are of Formula (3).
When R3, R4, R5, R6 or R7 is optionally substituted alkyl it is preferably optionally substituted C1-20-alkyl, more preferably optionally substituted C1-4-alkyl and especially optionally substituted C1-6-alkyl. Preferred optional substituents include hydroxy, carboxy, sulpho, xe2x80x94PO3H2, cyano, a 5 or 6 membered heterocyclic group and optionally substituted amino. Preferred 5 or 6 membered heterocyclic groups are optionally substituted furanyl and tetrahydrofuranyl, more preferably furanyl and tetrahydrofuranyl optionally substituted by xe2x80x94COOH or xe2x80x94SO3H.
Preferred optionally substituted amino groups which may be present on the alkyl groups represented by R3, R4, R5 and R6 are of the formula xe2x80x94NRaRb wherein Ra and Rb are each independently H; alkyl, more preferably C1-6-alkyl, especially C1-4-alkyl, more especially methyl, ethyl, n-propyl or iso-propyl; xe2x80x94CO(alkyl), preferably xe2x80x94CO(C1-6-alkyl), more preferably xe2x80x94CO(C1-4-alkyl), especially xe2x80x94COCH3, xe2x80x94COCH2CH3 and xe2x80x94COCH2CH2CH3; xe2x80x94C1-6hydroxyalkyl; or Ra and Rb together with the nitrogen to which they are attached form an optionally substituted morpholine, piperazine, pyrrolidine or piperidine ring.
When xe2x80x94NRaRb is a substituted morpholine or piperazine ring it preferably carries a substituent of the formula xe2x80x94Mxe2x80x94NR12R13 wherein M is an alkylene linking group and R12 and R13 each independently is H or C1-6alkyl optionally substituted by hydroxy, C1-6alkoxy or carboxy. M is preferably C1-6alkylene, more preferably C2-6-alkylene and especially xe2x80x94(CH2)gxe2x80x94, where g is from 2 to 6.
A preferred substituted piperazinyl group represented by xe2x80x94NRaRb is of the formula: 
wherein M, R12 and R13 are as hereinbefore defined.
Especially preferred substituted piperazinyl groups represented by xe2x80x94NRaRb are of the formula: 
A further preferred optionally substituted alkyl group represented by R3, R4, R5, R6 or R7 is of the Formula (4):
xe2x80x94(CaH2aO)p(CbH2bO)qR14xe2x80x83xe2x80x83Formula (4)
wherein:
R14 is H or alkyl;
a and b are different and from 1 to 6;
p is from 1 to 4; and
q is from 0 to 3.
Preferably R14 is H or C1-4-alkyl, more preferably H.
Preferably a and b are each independently 2 to 6, more preferably 2 or 3. p is preferably 1 or 2. Preferably q is 0.
Preferred groups of the Formula (4) are of the formula xe2x80x94(C1-6-alkylene)O(C1-6-alkylene)OC1-4alkyl or xe2x80x94(C2-6-alkylene)O(C2-6-alkylene)OH. Examples of such groups include xe2x80x94C2H4OC2H4OH, xe2x80x94C2H4OC2H4OCH3, xe2x80x94CH2CH(CH3)CH2OC2H4OH and xe2x80x94C3H6OC2H4OH.
When R3, R4, R5, R6 or R7 is optionally substituted aryl it is preferably optionally substituted phenyl or naphthyl, more preferably optionally substituted phenyl. Preferred optional substituents are C1-6-alkoxy, C1-6-alkyl, C1-6alkyl substituted by hydroxy, carboxy or sulpho, halogen (preferably F or Cl), hydroxy, cyano, carboxy, sulpho, xe2x80x94PO3H2, nitro, amino, xe2x80x94COC1-4-alkyl, xe2x80x94NHCOC1-4-alkyl, xe2x80x94SO2NH2 and xe2x80x94SO2NHCOC1-4-alkyl. More preferably the optionally substituted aryl group is of the formula: 
wherein:
R15 is C 1-4-alkyl, C1-4-alkoxy, halogen, carboxy, sulpho or xe2x80x94PO3H2; and
t is 0 to 5.
t is preferably 0, 1 or 2.
When R3, R4, R5 or R6 is optionally substituted aralkyl it is preferably of the formula: 
wherein R15 and t are as hereinbefore defined.
When R5 and R6 together with the nitrogen to which they are attached form an optionally substituted 5 or 6 membered ring it is preferably an optionally substituted piperidine, piperazine, pyrrolidine or morpholine ring, more preferably optionally substituted piperazine or morpholine. The optional substituents are preferably selected from hydroxy, carboxy, sulpho, C1-6alkoxy, C1-6-alkyl and C1-6-alkyl substituted by hydroxy, carboxy, sulpho and optionally substituted amino as hereinbefore defined. An especially preferred optional substituent is xe2x80x94Mxe2x80x94NR12R13 wherein R12 and R13 are as hereinbefore defined.
It is especially preferred that R7 is H or C1-4-alkyl optionally substituted by hydroxy, carboxy or sulpho.
R4 is preferably H or C1-4-alkyl.
The compound of Formula (1) preferably contains only two azo groups (xe2x80x94Nxe2x95x90Nxe2x80x94).
The preferred halogen represented by Z1 and/or Z2 is chlorine. It is however, preferred that Z1 and Z2 are, each independently, xe2x80x94SR3, xe2x80x94OR4 or xe2x80x94NR5R6, more preferably xe2x80x94SR3 or xe2x80x94NR5R6, and especially xe2x80x94SR3 or xe2x80x94NHR5, wherein R3, R4, R5 and R6 are as hereinbefore defined.
In view of the foregoing preferences with respect to Formula (1), preferred compounds of the first aspect of the present invention are of Formula (5) and salts thereof: 
wherein:
X3 and X4 are each independently an optionally substituted piperazinylene group, xe2x80x94Sxe2x80x94 or xe2x80x94NR7xe2x80x94;
L2 is group of the Formula (2) as hereinbefore defined, or C2-10-alkylene optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, phenylene, xe2x80x94NR8xe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94CO(O)xe2x80x94 or by an optionally substituted piperazinylene group; or
xe2x80x94X3L2X4xe2x80x94 forms an optionally substituted piperazinylene group; and
B1, B2, Z1, Z2, R7 and R8 are as hereinbefore defined.
The optionally substituted piperazinylene groups referred to in the definitions of X3, X4, L2 and xe2x80x94X3L2X4xe2x80x94 are preferably of Formula (3), as hereinbefore defined.
In a preferred compound of Formula (5) Z1=Z2=halogen (especially Cl), L2 is C2-6-alkylene (especially propylene), X3=X4=NH and B=B2=xe2x80x94SO3H.
The compounds of Formula (5) exhibit a high solubility in aqueous media and provide prints which exhibit high light-fastness and water-fastness when incorporated into inks for ink jet printing.
A particularly preferred embodiment of the present invention comprises a compound of Formula (5) and salts thereof wherein:
X3 and X4 are each independently xe2x80x94NR7xe2x80x94 or xe2x80x94Sxe2x80x94;
Z1 and Z2 are each independently xe2x80x94SR16 or xe2x80x94NR17R18;
R16 and R17 are each independently a group of the formula xe2x80x94(C1-6-alkylene)O(C1-6-alkylene)OR19 or C1-6-alkyl optionally substituted by C1-4-alkoxy, hydroxy, carboxy, sulpho, tetrahydrofuryl, morpholinyl or a group of the formula xe2x80x94NR19CO(C1-4-alkyl);
R19 is H or C1-4-alkyl;
R7 and R18 are independently H or C1-4-alkyl optionally substituted by hydroxy, carboxy or sulpho;
B1 and B2 are sulpho; and
L2 is as hereinbefore defined.
Preferably L2 is C2-10-alkylene optionally interrupted by xe2x80x94NR8xe2x80x94 wherein R8 is as hereinbefore defined, more preferably L2 is C2-4-alklene, and especially propylene.
For ease of synthesis B1 and B2 are preferably the same and Z1 and Z2 are preferably the same.
An especially preferred embodiment of the present invention comprises a compound of the Formula (6) and salts thereof: 
wherein:
a) both groups represented by Z are xe2x80x94NHCH2CH2OH; or
b) both groups represented by Z are Cl; or
c) one group represented by Z is Cl and the other is xe2x80x94NHCH2CH2OH.
We have found that mixtures comprising two or more compounds of Formula (1), especially those in which the compounds contain different values for Z1 and Z2 between the compounds of Formula (1), are particularly suitable for use in ink jet printing inks.
Accordingly, a second aspect of the present invention provides a composition comprising:
(a) from 1 to 99 parts of a compound of the Formula (1) as defined in the first aspect of the present invention, provided that Z1 and Z2 are each independently xe2x80x94SR3, xe2x80x94OR4 or xe2x80x94NR5R6;
(b) from 0 to 50 parts of a compound of the Formula (1) as defined in the first aspect of the present invention, provided that one of Z1 and Z2 is a labile atom or group and the other is xe2x80x94SR3, xe2x80x94OR4 or xe2x80x94NR5R6; and
(c) from 1 to 99 parts of a compound of the Formula (1) as defined in the first aspect of the present invention, provided that Z1 and Z2 are both a labile atom or group;
wherein R3, R4, R5 and R6 are as hereinbefore defined and all parts are by weight and the total number of parts of (a)+(b)+(c)=100.
The number of parts of component (a) is preferably from 20 to 80, more preferably 40 to 60. The number of parts of component (b) is preferably from 5 to 45 more preferably from 15 to 40. The number of parts of component (c) is preferably from 2 to 60, more preferably from 5 to 30 and especially from 10 to 30.
When Z1 and/or Z2 is a labile atom or group, it is preferably an atom or group which is displaceable by a hydroxyl group of cellulose under mildly alkaline aqueous conditions to form a covalent bond between the compound of the Formula (1) and cellulose.
Preferred labile atoms and groups which may be represented by Z1 and/or Z2 in the second aspect of the invention include halogen atoms, such as F or Cl; sulphonic acid groups; thiocyano groups; quaternary ammonium groups, for example trialkylammonium groups and optionally substituted pyridinium groups, for example 3- and 4-carboxy pyridinium groups. An especially preferred labile atom is Cl.
Preferably in component (a) Z1 and Z2 are identical. In component (c) Z1 and Z2 are preferably identical.
More preferably in component (a) Z1 and Z2 are identical; in component (c) Z1 and Z2 are identical (a); and in component (b) Z1 is identical to Z1 and Z2 in component (a) and Z2 is identical to Z1 and Z2 in component (c).
In preferred compositions according to the second aspect of the invention the compounds of the Formula (1) are of the Formula (5), or more preferably Formula (6) as hereinbefore defined.
The compositions of this second aspect have the attractive shade good light-fastness, good freeze-thaw properties, high stability at elevated temperatures and other properties of the compounds according to the first aspect of the invention, but they also benefit from greater solubility in ink media. This allows strongly coloured, storage stable inks to be prepared giving prints of high optical density. Surprisingly, wet-fastness is not adversely affected even though the compositions have high solubility in aqueous ink media.
An especially preferred composition comprises:
(a) from 40 to 60 parts of a compound of the Formula (5) or a salt thereof wherein Z1and Z2 are the same and of the formula xe2x80x94NHR17 wherein R17 is as hereinbefore defined (preferably C1-6alkyl optionally substituted by xe2x80x94OH, xe2x80x94SO3H, xe2x80x94COOH or tetrahydrofuryl);
(b) from 5 to 45 parts of a compound of the Formula (5) or a salt thereof wherein Z1 is Cl and Z2 is the same as Z2 in component (a); and
(c) from 10 to 30 parts of a compound of Formula (5) or a salt thereof wherein Z1 and Z2 are Cl;
wherein in Formula (5) B1 and B2 are xe2x80x94SO3H; L2 is the same in each of components (a), (b) and (c) and is C2-4-alkylene; X3 and X4 are NH; and all parts are by weight and the sum of the parts (a)+(b)+(c)=100.
In this especially preferred composition the compound of the Formula (5) is preferably of the Formula (6) as hereinbefore defined.
The compounds of the invention may be in the free acid or salt form. Preferred salts are water-soluble, for example alkali metal salts, especially lithium, sodium and potassium salts, ammonium and substituted ammonium salts. Especially preferred salts are salts with sodium, ammonia and volatile amines. The dyes may be converted into a salt using known techniques. For example, an alkali metal salt of a dye may be converted into a salt with ammonia or an amine by dissolving an alkali metal salt of the dye in water, acidifying with a mineral acid and adjusting the pH of the solution to pH 9 to 9. 5 with ammonia or the amine and removing the alkali metal cations by dialysis, reverse osmosis or ultrafiltration.
The compounds and composition according to the present invention may be, and preferably are, purified to remove undesirable impurities before they are incorporated into inks for ink jet printing. Conventional techniques may be employed for purifying the dyes, for example ultrafiltration, reverse osmosis and/or dialysis.
The compounds of the invention may be prepared using conventional techniques for the preparation of azo dyes. For example a suitable method comprises condensing a compound of the Formula HQH with approximately 2 molar equivalents of a compound of the Formula (7): 
wherein Q, B, R1 and Z1 are as hereinbefore defined.
The compound HQH is preferably of the formula HX1LX2H wherein X1, X2 and L are as hereinbefore defined.
The condensation is preferably performed in a liquid medium, more preferably an aqueous medium and especially water. Temperatures of 15xc2x0 C. to 100xc2x0 C. are preferred, more preferably from 30 to 40xc2x0 C. The reaction time is preferably from 1 to 48 hours, more preferably from 3 to 24 hours.
The condensation is preferably performed in the presence of a base. The base may be any inorganic base for example, ammonia, an alkali metal or alkali earth metal hydroxide, carbonate or bicarbonate, or an organic base. Preferred organic bases are tertiary amines for example, N-alkylated heterocycles, for example Nxe2x80x94(C1-4-alkyl)-morpholine, Nxe2x80x94(C1-4-alkyl)piperidine, N, Nxe2x80x2-di(C1-4-alkyl)piperazine; tri(C1-4-alkyl)amines, for example triethylamine, and optionally substituted pyridines, especially pyridine.
The amount of base used may be varied between wide limits but it is preferred to use less than 40, more preferably less than 10 and especially from 3 to 5 moles for each mole of the compound of Formula (7).
After the condensation the product may be isolated by precipitating the product as a salt from the reaction mixture for example by the addition of a suitable alkali metal salt, especially sodium chloride. Alternatively, the product may be isolated in its free acid form by acidifying the reaction mixture, preferably using a mineral acid, especially hydrochloric acid. Where the product precipitates as a solid it may be separated from the mixture by filtration.
If desired unwanted anions may be removed from the product of the above process by dialysis, osmosis, ultrafiltration or a combination thereof.
The product of the above process may be converted, if desired, to the NH4+, quaternary ammonium or organic amine salt by the addition of ammonia, ammonium hydroxide, primary, secondary, tertiary or quaternary amine. When the base used in the condensation process is an organic amine an excess may be used so that the compound of Formula (1) is formed as the organic amine salt.
The compound of the Formula (7) may be prepared using conventional techniques, for example by:
(1) diazotising a compound of the Formula (8) to give the corresponding diazonium salt: 
wherein R1 and B1 is as hereinbefore defined;
(2) coupling the diazonium salt from stage (1) with 2-amino-8-naphthol-6-sulphonic acid at a pH less than 7, preferably at a pH of from 3 to 5;
(3) hydrolysing the product of stage (2) under alkaline conditions to give a compound of the Formula (9): 
(4) condensing the product from stage (3) with approximately 1 molar equivalent of the compound of the formula: 
wherein A is as hereinbefore defined; and
(5) condensing the product from stage (4) with approximately 1 molar equivalent of the compound of the formula Z1H.
The diazotisation in stage (1) is preferably performed in an aqueous medium at a pH below 7 in the presence of a suitable diazotisation agent. Dilute mineral acid, e. g. HCl or H2SO4, is preferably used to achieve the desired acidic conditions. Conveniently the diazotisation agent is formed in-situ, for example by dissolving an alkali metal nitrite, preferably sodium nitrite, in a molar excess of mineral acid, preferably HCl. Normally at least one mole of diazotisation agent per mole of the compound of Formula (8), preferably from 1 to 1.25 moles will be used in the diazotisation.
The temperature of the diazotisation is not critical and may conveniently be carried out at from xe2x88x925xc2x0 C. to 20xc2x0 C. , preferably from 0 to 10xc2x0 C. and especially from 0 to 5xc2x0 C.
The hydrolysis in stage (3) is preferably performed at a pH of from 9 to 14. The temperature during hydrolysis is preferably 40 to 90xc2x0 C.
When B1 and B2, R1 and R2 or Z1 and Z2 are different, the compounds of Formula (1) are preferably prepared by condensing a compound of the Formula (7) with an approximately equimolar quantity of the compound of the formula HQH (preferably HX1LX2H). The product of this reaction is then further condensed with an approximately equimolar quantity of a compound of the Formula (7) wherein R1 is R2, B1 is B2 and Z1 is Z2 as hereinbefore defined.
Alternatively, a compound of Formula (1) or Formula (5) in which one or both of Z1 and Z2 are other than halogen, may be prepared by condensing a compound of Formula (1) or Formula (5), in which Z1=Z2=Cl, with sufficient of a compound or compounds Z1H and/or Z2H, wherein Z1 and Z2 are as hereinbefore defined except for Cl, under such conditions of temperature and/or time as to replace one or both Cl atoms.
The compositions according to the second aspect of the invention comprising components (a) and (c) can be prepared by mixing together the two components prepared as hereinbefore described. When the composition according to the second aspect of the invention comprises components (a), (b) and (c) it is preferably prepared by reacting the compound of Formula (7) in which both Z1 and Z2 are Cl with insufficient of the compound Z1H (in which Z1 is not Cl) and/or under such temperature and/or temperature conditions as not to replace all the Cl atoms in the compound of Formula (7) to give a mixture of non-reacted, mono- and di-reacted products.
The compounds of Formula (1) may exist in tautomeric forms other than those shown in this specification. These tautomers are included within the scope of the present claims.
According to a third aspect of the present invention there is provided an ink comprising:
(a) from 0.01 to 30 parts in total of one or more compounds of the Formula (1), as hereinbefore defined, with the proviso that Z1 and/or Z2 may also be a labile atom or group; and
(b) from 70 to 99.99 parts of a medium comprising a mixture of water and an organic solvent, an organic solvent free from water, or a low melting point solid;
wherein all parts are by weight and the number of parts of (a)+(b)=100.
Preferred labile atoms and groups which may be represented by Z1 and/or Z2 are as hereinbefore defined in the second aspect of the present invention, especially chloro.
When component (a) of the ink is a mixture of more than one compound of Formula (1) or (5) it is preferably from 2 to 8, more preferably 2 or 3, especially 3 compounds of Formula (1) as defined in the second aspect of the present invention, and more especially is a two or three component mixture as hereinbefore defined in relation to the second aspect of the present invention.
In the inks according to the third aspect of the present invention component (a) of the ink is preferably a compound of the Formula (5), more preferably of the Formula (6), as hereinbefore defined in relation to the first aspect of the invention. It is especially preferred that component (a) of the ink is a composition according to the second aspect of the present invention.
The number of parts of component (a) is preferably from 0.1 to 20, more preferably from 0.5 to 15, and especially from 1 to 5 parts. The number of parts of component (b) is preferably from 99.9 to 80, more preferably from 99.5 to 85, especially from 99 to 95 parts.
When the medium is a mixture of water and an organic solvent or an organic solvent free from water, preferably component (a) is completely dissolved in component (b). Preferably component (a) has a solubility in component (b) at 20xc2x0 C. of at least 10%. This allows the preparation of concentrates which may be used to prepare more dilute inks and reduces the chance of the dye precipitating if evaporation of the liquid medium occurs during storage.
When the medium comprises a mixture of water and an organic solvent, the weight ratio of water to organic solvent is preferably from 99:1 to 1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to 80:20.
It is preferred that the organic solvent present in the mixture of water and organic solvent is a water-miscible organic solvent or a mixture of such solvents. Preferred water-miscible organic solvents include C1-6-alkanols, preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol and cyclohexanol; linear amides, preferably dimethylformamide or dimethylacetamide; ketones and ketone-alcohols, preferably acetone, methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscible ethers, preferably tetrahydrofuran and dioxane; diols, preferably diols having from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferably diethylene glycol, triethylene glycol, polyethylene glycol and polypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol; mono-C1-4-alkyl ethers of diols, preferably mono-C1-4-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol, 2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether; cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclic esters, preferably caprolactone; sulphoxides, preferably dimethyl sulphoxide and sulpholane. Preferably the liquid medium comprises water and 2 or more, especially from 2 to 8, water-soluble organic solvents.
Especially preferred water-soluble organic solvents are cyclic amides, especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone; diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol, diethyleneglycol and triethyleneglycol; and mono-C1-4-alkyl and C1-4-alkyl ethers of diols, more preferably mono-C1-4-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxy-2-ethoxy-2-ethoxyethanol.
A preferred medium comprises:
(a) from 75 to 95 parts water; and
(b) from 25 to 5 parts in total of one or more solvents selected from diethylene glycol, 2-pyrrolidone, thiodiglycol, N-methylpyrrolidone, cyclohexanol, caprolactone, caprolactam and pentane-1,5-diol;
wherein the parts are by weight and the sum of the parts (a) and (b)=100.
Examples of further suitable ink media comprising a mixture of water and one or more organic solvents are described in U.S. Pat. Nos. 4,963,189, 4,703,113, 4,626,284, EP 425,150A and U.S. Pat. No. 5,207,824.
When the liquid medium comprises an organic solvent free from water, (i. e. less than 1% water by weight) the solvent preferably has a boiling point of from 300 to 200xc2x0 C., more preferably of from 40xc2x0 to 150xc2x0 C., especially from 50 to 125xc2x0 C. The organic solvent may be water-immiscible, water-miscible or a mixture of such solvents. Preferred water-miscible organic solvents are any of the hereinbefore described water-miscible organic solvents and mixtures thereof. Preferred water-immiscible solvents include, for example, aliphatic hydrocarbons; esters, preferably ethyl acetate; chlorinated hydrocarbons, preferably CH2Cl2; and ethers, preferably diethyl ether; and mixtures thereof.
When the liquid medium comprises a water-immiscible organic solvent, preferably a polar solvent is included because this enhances solubility of the dye in the liquid medium. Examples of polar solvents include C1-4-alcohols. In view of the foregoing preferences it is especially preferred that where the liquid medium is an organic solvent free from water it comprises a ketone (especially methyl ethyl ketone) and/or an alcohol (especially a C1-4-alkanol, for example ethanol or propanol).
The organic solvent free from water may be a single organic solvent or a mixture of two or more organic solvents. It is preferred that when the medium is an organic solvent free from water it is a mixture of 2 to 5 different organic solvents. This allows a medium to be selected which gives good control over the drying characteristics and storage stability of the ink.
Ink media comprising an organic solvent free from water are particularly useful where fast drying times are required and particularly when printing onto hydrophobic and non-absorbent substrates, for example plastics, metal and glass.
Preferred low melting solid media have a melting point in the range from 60xc2x0 C. to 125xc2x0 C. Suitable low melting point solids include long chain fatty acids or alcohols, preferably those with C18-24 chains, and sulphonamides. The dye of Formula (5) may be dissolved in the low melting point solid or may be finely dispersed in it.
The dyes according to the present invention exhibit a high solubility in aqueous media, accordingly it is preferred that the liquid medium is a mixture of water and one or more water miscible organic solvent(s).
The ink and composition may also contain additional components conventionally used in ink jet printing inks, for example viscosity and surface tension modifiers, corrosion inhibitors, biocides, kogation reducing additives, anti-cockle agents to reduce paper curling and surfactants which may be ionic or non-ionic.
When the inks according to the third aspect of the invention are used as ink jet printing inks, the ink preferably has a concentration of less than 100 parts per million, more preferably less than 50 parts per million, in total of halide ions and divalent and trivalent metals. This reduces nozzle blockage in ink jet printing heads, particularly in thermal ink jet printers.
A fourth aspect of the present invention provides a process for printing an image on a substrate comprising applying thereto an ink containing a compound or a composition a according to the first or second aspect of the invention by means of an ink jet printer.
The ink used in this process is preferably as defined in the third aspect of the present invention, especially where component (a) is a composition according to the second aspect of the present invention.
The ink jet printer preferably applies the ink to the substrate in the form of droplets which are ejected through a small orifice onto the substrate. Preferred ink jet printers are piezoelectric ink jet printers and thermal ink jet printers. In thermal ink jet printers, programmed pulses of heat are applied to the ink in a reservoir by means of a resistor adjacent to the orifice, thereby causing the ink to be ejected in the form of small droplets directed towards the substrate during relative movement between the substrate and the orifice. In piezoelectric ink jet printers the oscillation of a small crystal causes ejection of the ink from the orifice.
The substrate is preferably paper, plastic, a textile, metal or glass, more preferably paper, an overhead projector slide or a textile material, especially paper.
Preferred papers are plain or treated papers which may have an acid, alkaline or neutral character. Examples of commercially available treated papers include HP Premium Coated Paper (available from Hewlett Packard Inc), HP Photopaper (available from Hewlett Packard Inc), Stylus Pro 720 dpi Coated Paper, Epson Photo Quality Glossy Film (available from Seiko Epson Corp.), Epson Photo Quality Glossy Paper (available from Seiko Epson Corp.), Canon HR 101 High Resolution Paper (available from Canon), Canon GP 201 Glossy Paper (available from Canon), and Canon HG 101 High Gloss Film (available from Canon).
A fifth aspect of the present invention provides a substrate, preferably a paper, an overhead projector slide or a textile material, printed with an ink according to the third aspect of the present invention or by means of the process according to the fourth aspect of the present invention, or coated with a compound according to the first aspect of the present invention or a composition according to the second aspect of the present invention.
When the substrate is a textile material the ink according to the third aspect of the present invention preferably contains one or more compounds according to the first aspect or compositions according to the second aspect having at least one, and more preferably two, labile group or atom. Such an ink is preferably applied to the textile material by an ink jet printer followed by heating the printed textile material at a temperature of from 50xc2x0 C. to 250xc2x0 C.
Preferred textile materials are natural, synthetic and semi-synthetic materials. Examples of preferred natural textile materials include wool, silk, hair and cellulosic materials, particularly cotton, jute, hemp, flax and linen. Examples of preferred synthetic and semi-synthetic materials include polyamides, polyesters, polyacrylonitriles and polyurethanes.
The textile material is preferably pre-treated with an aqueous pre-treatment composition comprising a thickening agent and optionally a water-soluble base and a hydrotropic agent and dried prior to applying the ink. The pre-treatment composition preferably comprises a solution of the base and the hydrotropic agent in water containing the thickening agent. Particularly preferred pre-treatment compositions are described in EP 534,660A.
According to a sixth aspect of the present invention there is provided an ink jet printer cartridge containing an ink, characterised in that the ink contains a compound of the Formula (1) as defined in the first aspect of the invention, or a composition according to the second aspect of the invention.
Preferably the ink contained in the ink jet printer cartridge is an ink according to the third aspect of the present invention.
The invention is further illustrated by the following Examples in which all parts and percentages are by weight unless otherwise stated.